Hinge for crane boom



April 16, 1963 c. A. MILLER HINGE FOR CRANE BOOM 2 SheetsSheet 1 Filed March 23, 1961 R M M W. A M C @Zw flaw/wand ATTOP/VEVS April 1963 c. A. MILLER 3,085,695

HINGE FOR CRANE BOOM Filed March 25, 1961 2 Sheets-Sheet 2 1 INVENTOR. 74 5 C491 A. M/LLEE z/ wmww% ATTOP/VEVS 3,985,695 Patented Apr. 16, 1963 3,0855% HINGE FOR CRANE BOOM Carl A. Miller, Watson Township, Allegan County, Mich. (Rte. 2, Hopkins, Mich.) Filed Mar. 23, 1961, Ser. No. 97,813 3 Claims. (Cl. 212-444) This invention relates to improvements in booms for portable cranes, power shovels, derricks and the like and, more particularly, relates to an improved boom comprised of a plurality of end-to-end arranged sections which are held in selectable angular positions with respect to each other by a novel connector structure.

Cranes, shovel, derricks and the like are conventionally mounted either on motor trucks or on caterpillar track vehicles for self-prope1led movement. Because of the length of the boom used on such apparatus and due to the fact that the boom is ordinarily upwardly inclined during movement thereof, the outer end of same normally is located a substantial distance above the ground and may interfere with movement thereof under bridges and in other situations where a limited overhead clearance is available. While boom structures can be dismantled in order to avoid this problem, such dismantling is time consuming and is relatively expensive because of the labor costs involved.

A number of boom structures employing hingedly connected sections have been proposed heretofore in order to overcome this problem but none of these has proven completely satisfactory. In some instances the hinge structures are unduly complicated and thus are relatively expensive both to install and to maintain in proper operating condition. A particularly important deficiency in the prior art hinged boom structures is that none of them, insofar as I am aware, provide any means, as part of the hinge structure, to prevent the hinging movement of the boom sections with respect to each other past a certain point when the relative positions of the boom sections are being adjusted. This, in turn, means that a number of workmen are required to hold the outer boom section and prevent its outer end from falling to the ground. Moreover, there is the constant danger that through inadvertence or accident the outer boom section will be permitted to fall to the ground and thereby be damaged and possibly injure workmen. Further, many prior hinged-boom structures are such that it is necessary to support the outer boom section by someauxiliary mechanism, such as a support post, while the boom is being transported. While it is possible to provide such special supports, at extra expense, on relatively small cranes mounted on trucks, such is not possible where the boom is mounted on a self-propelled, caterpillar-track type vehicle and the like where the'boom projects far beyond the operators cab and the ground-engaging structure associated therewith.

Accordingly, it is an object of this invention to provide an improved boom structure having hingedly connected sections and an improved connector structure for holding the boom sections in selectable angular positions with respect to each other.

It is a further object of this invention to provide an improved boom structure, as aforesaid, in which the connector structure includes positive means for limiting downward movement of the outer boom section.

It is a further object of this invention to provide an improved boom structure, as aforesaid, which is such that the hinge joint and the connector structure can be readily added to existing boom structures or can be incorporated in new boom structures at a minimum of expense.

It is a further object of this invention to provide an improved boom structure, as aforesaid, in which the outer boom section can be supported in a plurality of angular positions with respect to the inner boom section.

It is a further object of this inveniton to provide an improved boom structure, as aforesaid, in which the hinge joint and the connector structures are comprised of a few, relatively simple and sturdy parts and which, therefore, can be manufactured inexpensively, which will have a long, useful life and which can be operated easily by unskilled workmen.

Other objects and advantages of the invention will be apparent to persons acquainted with equipment of this type upon reading the following description and inspecting the accompanying drawings, in which:

FIGURE 1 is a side elevational view of a fragment of a boom construction embodying the invention, the boom sections being shown in longitudinally aligned positions.

FIGURE 2 is a view similar to FIGURE 1 and showing the boom sections in non-aligned positions with respect to each other.

FIGURE 3 is a simplified, top plan view of the boom construction, the pads and binge structure not being shown in order that the details of the connector structure will appear more clearly.

' FIGURE 4 is a sectional view taken along the line IVIV in FIGURE 3.

' FIGURE 5 is a sectional View taken along the line VV of FIGURE 4.

FIGURE 6 is a schematicview of a crane embodying the boom construction of the invention.

Referring to the drawings, there is shown a boom structure 10 comprised of a pair of end-to-end arranged boom sections 11 and 12 which are hingedly connected at their adjacent ends. The inner boom section, here the section 11, will be mounted inany suitable, conventional fashion upon a movable support therefor, such as a motor truck or self-propelled, caterpillar-track type vehicle as shownat 7 in FIGURE 6. Ordinarily, this section will be mounted for vertical movement as well as movement about a horizontal axis. The support for the boom sec tion 11 may include an operators cab 8 containing the usual controls for operating a tool, such as a shovel (not shown), mounted on the remote end of the outer boom section12, all in accordance with conventional practice. Ordinarily, operation of the tool is effected by the cables 9 but these are not shown in greater detail because they are conventional and form no part of the present invention.

The boom section 11 is here shown as being made from structural members arranged in rectangular cross section and comprises four longitudinally-extending angle members at the corners thereof, three of which are shown at 13, 14 and 16. The angle members are connected together by braces 17 and '18 in a conventional fashion. The boom section 12 is similarly constructed and corresponding parts thereof are indicated by the same reference numerals as applied to boom section 11 with the sufiix a added thereto.

The hinge structure 20 includes a pair of hinge plates 21 and 22 (FIGURES 1 and 2) which are secured, as by welding, to the surfaces 23 and 23a of the lower angle members 14- and 14a and said plates extend toward, are offset from and overlap each other. The plates 21 and 22 each have an opening therethrough and said openings are in alignment. A hinge pin 24 extends through the aligned openings and connects the plates 21 and 22 and thereby the boom sections 11 and 12 for pivotal movement with respect to each other. A corresponding hinge structure is provided at the other, lower corner (not shown) of the boom 10. Thus, the boom section 12 is supported for pivotal movement with respect to the boom section 11.

A pair of adjustable connections 26 and 27 (FIG- URE 3) are provided at the respective upper corners of the boom sections 11 and 12. Since these connections are identical, only the connection 26 will be described in detail herein and it will be understood that such description will apply in substance to the connection 27.

The connection 26 (FIGURE 3) comprises a pair of upstanding brackets 31 and 32 which are secured, as by welding, to the upper surface 33 of the angle member 13 and which are arranged in parallel, spaced relation. The brackets 31 and 32 have aligned openings there through, one of which appears at 30 (FIGURE 2). A similar pair of brackets 34 and 36 (FIGURE 3) are secured in a similar fashion to the upper surface 33a of angle member 13a and are in alignment with the brackets 31 and 32, respectively. The brackets 34 and 36 also have aligned openings therethrough, one of which appears at 35 (FIGURE 2). The adjacent ends of the brackets 31, 32, 34 and 36 (FIGURE 3) are located so that they will permit the boom sections 11 and 12 to move into longitudinal alignment as shown in FIGURE 1. In this particular embodiment of the invention, such longitudinal alignment occurs when the pads 37, 38, 39 and 41 on the boom sections 11 and 12 abut against each other. Corresponding pads are pro vided on the other side of the boom sections for the same purpose.

A link 42 has one of its ends located between the brackets 34 and 36 and its other end extends between the brackets 31 and 32. The link 42 has a series of spaced open ings 43, 44, 45 and 46 therethrough. Opening 43 is aligned with the openings in the brackets 34 and 36 and the hinge pin 47 extends therethrough. The hinge pin 47 is held in such position by the cotter pins 48. The other openings 44, 45 and 46 are selectably and alternately alignable with the openings in the brackets 31 and 32. Opening 44 is aligned therewith when the boom sections 11 and 12 are in longitudinal alignment, as shown in FIGURE 1, and openings 45 and 46 are aligned therewith when the boom section 12 is inclined with respect to boom section 11 at a relatively small angle and at a larger angle, respectively. In the position of the parts shown in FIGURES 2 through 5, opening 46 is aligned with the openings in the brackets 31 and 32. A pin 51 extends through opening 46 and the openings in the brackets 31 and 32 and holds the boom sections 11 and 12 in inclined positions. The pin 51 is releasably held in said openings by the cotter pins 52.

A stop bar 53 (FIGURES 3 and 4) is secured, as by welding, to the upper ends of the brackets 31 and 32 and extends therebetween. The link 42 has an upstanding projection 54 having a surface 56 which is engageable with the stop bar 53. As shown in FIGURES 2-5, when the boom section 12 is in its maximum inclined position with respect to the boom section 11, the surface 56' is spaced a slight distance from stop 53. If the pin 51 were to be removed and the boom section 12 were not supported, said boom section would pivot downwardly until the surface 56 engages the stop 53 and then further movement thereof would be blocked. It will be observed that the link 42 substantially fills the space between the upper surface 33 of the angle member 13 and the stop bar 53 and cannot accidentally be removed from between the brackets 31 and 32. Thus, the section 12 cannot pivot downwardly past a certain point and this is arranged so that the section 12 will be held a predetermined distance above the ground. Thus, the possibility of injury to the boom section 12 due to improper handling thereof is effectively minimized.

The hinge structure 20 and the connections 26 and 27 can be made integral parts of the boom sections 11 and 12 during manufacture thereof or they can be attached to existing boom structures in any suitable manner, such as by welding the parts thereof to said boom sections.

In use, the hinge pin 47 will ordinarily be relatively permanently mounted in the opening 43 and associated openings in the brackets 34 and 36. The inclination of the boom section 12 with respect to the boom section 11 can be adjusted by removing pin 51 and the corresponding pin in connection 27 and moving said boom section 12 and the link 42 so that the proper one of the openings 44, 45 and 46 is moved into alignment with the openings in the brackets 31 and 32. This is effected by manually pivoting the boom section 12 upwardly or downwardly about the axis of the hinge pin 24. If, during this operation, the boom section should be released for any reason, the same would pivot downwardly until surface 56 abuts against the stop 53 and then further movement thereof would be blocked. If it should be desired to entirely remove the boom section 12 from the boom section 11, the same can be done by removing pins 24, 47 and 51 and the corresponding pins on the other side of the boom sections. This entirely disconnects the boom section 12 from the boom section 11 and said boom section 12 can then be handled by the workmen as desired.

While a particular preferred embodiment of the invention has been disclosed hereinabove, the invention contemplates such changes or modifications therein as lie within the scope of the appended claims.

What is claimed is:

'1. A boom structure comprising: a pair of elongated boom sections; hinge means pivotally connecting one boom section to the other for swinging movement with respect thereto; link means mounted on one boom section and extending toward the other boom section; pin means for releasably securing said link means to said other boom section in one of a number of selectable positions to thereby hold said boom sections in selected positions with respect to each other; stop means mounted on said other boom section and cooperating abutment means on said link means for engaging said stop means and thereby limiting movement of said boom sections with respect to each other past a predetermined point when said pin means is removed.

2. A boom structure comprising: a arranged, elongated boom sections having upper and lower edges, one of said boom sections being supported in cantilevered fashion at one end thereof and the other boom section being mounted on the other end of said one boom section; hinge means pivotally connecting one boom section to the other along the corresponding lower edges thereof for vertical swinging movement with respect thereto, the entirety of said hinge means being disposed below the lower edges of said boom sections whereby said boom sections can be disposed one above the other in substantial parellelism with each other; a link pivotally mounted on one boom section adjacent the upper edge thereof and extending toward the other boom section, said link having a series of spaced holes therethrough; a pin removably mounted on the other boom section and being receivable through one of said holes at a time to thereby lock said boom sections in position with respect to each other; a stop mounted on said other boom section adjacent said link; and an abutment on said link engageable with said stop to limit movement of said boom sections with respect to each other when said pin is removed.

3. A boom structure comprising: a pair of elongated boom sections which are generally rectangular in cross section and which have upper and lower edges, one of said boom sections being supported in cantilevered fashion at one end thereof and the other boom section being mounted on the other end of said one boom section; hinge means pivotally pair of end-to-end connecting one boom section to the other along the corresponding lower edges thereof for vertical swinging movement with respect thereto, the entirety of said hinge means being disposed below the lower edges of said boom sections whereby said boom sections can be disposed one above the other in substantial parallelism with each other; a plurality of connector structures mounted on the upper edges of said boom sections -for holding same at selectable distances from each other, each of said connector structures including a first pair of spaced brackets mounted on one boom section and a second pair of spaced brackets mounted on the other boom section, each of said pairs of brackets having aligned openings therethrough; a link having one end thereof located between one pair of brackets and the other end thereof located between the other pair of brackets, said link having a series of spaced holes therethrough, one of said holes being aligned with 10 the openings in one pair of brackets and the others of said holes being selectively alignable, one at a time, with the openings in the other pair of brackets; a first pin extending through said one hole and the openings in said one pair of brackets and thereby securing one end of said 15 link to one boom section; a removable second pin extending through the openings in the other pair of brackets and through one of said other holes in said link; a stop bar secured to and extending between said other pair of brackets above said link; said link having an upstanding abutment located on the side of said stop bar remote from the adjacent ends of said brackets and being engageable with said stop bar to limit swinging movement of said sections when said second pin is removed.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A BOOM STRUCTURE COMPRISING: A PAIR OF ELONGATED BOOM SECTIONS; HINGE MEANS PIVOTALLY CONNECTING ONE BOOM SECTION TO THE OTHER FOR SWINGING MOVEMENT WITH RESPECT THERETO; LINK MEANS MOUNTED ON ONE BOOM SECTION AND EXTENDING TOWARD THE OTHER BOOM SECTION; PIN MEANS FOR RELEASABLY SECURING SAID LINK MEANS TO SAID OTHER BOOM SECTION IN ONE OF A NUMBER OF SELECTABLE POSITIONS TO THEREBY HOLD SAID BOOM SECTIONS IN SELECTED POSITIONS WITH RESPECT TO EACH OTHER; STOP MEANS MOUNTED ON SAID OTHER BOOM SECTION AND COOPERATING ABUTMENT MEANS ON SAID LINK MEANS FOR ENGAGING SAID STOP MEANS AND THEREBY LIMITING MOVEMENT OF SAID BOOM SECTIONS WITH RESPECT TO EACH OTHER PAST A PREDETERMINED POINT WHEN SAID PIN MEANS IS REMOVED. 